This invention relates to an apparatus and method for dissolving a dry powder formulation in a liquid to form a solution. More particularly, the invention relates to an apparatus and method for circulating and agitating a solution used as a fountain solution in lithographic printing operations so as to ensure that a powder formulation is completely dissolved and remains in solution even while the solution is being dispensed from the apparatus.
Such a dry powder formulation used in lithographic fountain solutions has been delevoped by Canale et al. and is the subject of a related copending application, Ser. No. 890,018 filed Mar. 24, 1978, the disclosure of which is hereby incorporated by reference.
In lithographic printing processes, such as in lithographic printing of newspapers, brochures and the like, fountain solutions are used in the lithographic presses to replenish the desensitized area of lithographic plates, to clean the surface of the plates and to continuously maintain the non-printing area of such plates water receptive or hydrophilic.
Prior to the dry formulation disclosed in the Canale et al. application, alkali fountain solutions were premixed and shipped to printing sites in drums. Since such solutions are primarily water, the drums were heavy, bulky and difficult to handle. Furthermore, shipping costs for the drums were high. With the development of the dry powder formulation, which eliminates the high shipping costs and the bulky and heavy drums, a safe, simple and efficient apparatus and method for preparing the fountain solution at the printing site was needed.